Portal de Periódicos da CAPES

Understanding the Difference in Oxidative Properties between Flame and Diesel Soot Nanoparticles: The Role of Metals

2005; American Chemical Society; Volume: 39; Issue: 11 Linguagem: Inglês

10.1021/es048828z

1520-5851

Sung Hyun Kim, Robert A. Fletcher, Michael R. Zachariah,

Biodiesel Production and Applications

The purpose of this paper is to address the differences observed in the oxidative kinetics between flame and diesel derived soots. In particular, it has been observed that flame soot has a significantly higher activation energy for oxidation than does diesel soot. The hypothesis tested in this paper is that metals, possibly coming from lubricating oils, within diesel generated soot particles may be responsible for this effect. This is supported by the fact that addition of metal additives to diesel fuel is shown to have no effect on the activation energy of soot oxidation. The subject of this paper lies in testing the hypothesis by adding metal directly to a flame and extracting oxidation kinetics. Using a high temperature oxidation tandem differential mobility analyzer (HTO-TDMA) we extract particle size dependent kinetics for the oxidation of flame-derived soot doped with and without iron. We found that indeed addition of iron to a flame reduced the activation energy significantly from ∼162 ± 3 kJ/mol to ∼116 ± 3 kJ/mol, comparable with diesel engine generated soot with an activation energy ∼110 kJ/mol. These results are consistent with the idea that small quantities of metals during diesel combustion may play an important role in soot abatement.